Could not unmount /dev/sda1 with root filesystem

Question

Could not unmount /dev/sda1 with root filesystem.
When I try to resize it by unmounting but the following error message pops up:

The partition could not be unmounted from the following mount points:

/

Most likely other partitions are also mounted on these mount points. You are advised to unmount them manually.

How to go about?

Solution 1

To resize/move partitions, the best way is to boot from LiveCD/LiveUSB. Then use Gparted to manage partitions. You might need to install it, so do sudo apt-get install gparted.

There is a way to unmount your root partition on running system but I advise you not to do it because it is risky for your data.

Solution 2

You can't unmount it, because it's being used. From the error message, /dev/sda1 is the location of your root directory /. Instead, create a gparted live CD, then boot from that. Then, you should be able to resize the (now-unused) root partition.

Make sure you back everything up before resizing!

Comments

[Martin Thornton]

No, it won't. Do you ever test what you post?